Air-separator



T. J. STURTEVANT.

AIR SEPARATOR.

APPLICATION FILED FEB. 16. 1,920.

1,379,730. Patented May 31L, 1921.

S'EA'E'E FATENT THOMAS J. STUBTEVANT,.OF WELLESLEY, Ii IASSACI-IUSETTS, ASSIG-NOR TO STURTE- VANT MILL COIEPANY, 0F BOSTON, lv'IASSACI-IUSETTS, A CORPORATION 035 IEASSA- GHUSETTS.

AIR-SEPARATOB.

Specification of Letters Patent.

Patented May 31, 1921.

Application filed February 16, 1920. Serial No. 358,984.

To all whom it may concern.-

Be it known that I, THOMAS J. S'rUn'rE- VANT, a citizen of the United btates, residing at Wellesley, in the county of Norfolk and State of Massachusetts, have invented an Improvement in Air-Separators, of which the following description, in connection with the accompanying drawings, is a specification, like characters on the drawings representing like parts.

The invention to be hereinafter described I relates to air separators for grading materials. Separators of this general type have a separating chamber in communication with a collecting chamber. A fan causes an air current to move upward through the separating chamber and into the collecting chamber. The materials to be graded are introduced into the path of the rising air current, and the heavier particles or tailings gravitate downward through the rising air current, while the lighter particles or fines are carried along by the air current into the col lecting chamber. The separating chamber and the collecting chamber are provided with outlets through which the tailings and the fines may be delivered respectively.

One of the purposesof the present invention is to provide a simple and efiicient separator construction whereby the rising air current may be caused to whirl upward in a spiral path, the location of the fan being such that the air current may pass a substantial distance above the fan before leaving the casing of the separator, in order that the fines may have ample time to gravitate downward through the air current in the collecting chamber and thereby desirably clean the air of the particles before the air current leaves the collecting chamber.

Another purpose of the invention is to provide a bypass or pas'sagefor conducting the air current from the collecting chamber back to the separating chamber, so that the air current may pass in a closed circuit through the separating chamber, the col lecting chamber and the bypass or passage, said air current being produced by the fan which may be located in the opening between the separating and collecting chambers.

Another purpose of the invention is to provide guiding means, in the present in stance, in the form of a conical casing inter mediate the fan and the top of the separator to cooperate with the casing of the colance of the air current from the opening between the chambers to the mouth of the bypass or passage for conducting the air cur rent from the collecting chamber back to the separating chamber. 7

With the aforesaid and other purposes in view, the character of the invention may be best understood by reference to the following description of one good form of the invention shown in the accompanying drawing, wherein the separator is shown in vertical section.

Referring to the drawing, the separator shown therein comprises a casing 1 having a lower conical wall 3 and an upper conical wall 5 meeting and secured together by bolts 7 and diverging from their juncture for a purpose to be described. The lower conical wall 3 tapers downward to a discharge outlet 9 for the lines, and the upper conical wall 5 tapers upwardly and is provided with a head 11. The casing may be supported by feet 13 adapted to rest on beams or other appropriate means.

Mounted within the outer casing described, is an inner casing 15, in the present instance, comprising a lower conical wall '17 and an upper conical wall 19 meeting and secured together, and diverging from their juncture for a purpose to be described. The inner wall may be supported by brackets 21 interposed between the upper conical wall 3 and the lower conical wall 17 and conven iently opposite the casing supporting brackets 13. The inner casing 15 divides the outer easing into a separating chamber 23 and a collecting chamber 25.

Suitable means may be provided to introduce the materials to be graded into the separator. To accomplish this, in the present instance, a hopper 27 may be provided communicating with a feed tube '29 depending from said hopper a substantial distance into the separating chamber.

Suitable means may be provided to receive the materials from the feed tube and to distribute the same into the separating chamber. This means, in the present instance, comprises a rotary table or disk 31 having a hub 33 mounted 011 the upper end of a vertical shaft 35 journaled in an upper bearing 37 and a step bearing 39 carried by a casing 41. Fast on the vertical shaft is a bevel gear 43 meshing with and driven jecting from the casing 41 through the inner casing Wall 17 and the outer casing wall 3. The tube 49 may have wide flanges 51 and 53 secured to said walls, the construction being such that the tube 49 may be readily inserted into its operative position or removed therefrom,'thereby facilitating access to the bevel gears for the purpose of substituting new ones therefor when desired. At the outer end of the horizontal shaft 47 is a pulley 55 which may be driven by a belt from any suitable source of power.

The construction is such that materials falling through the feed tube 29 onto the rotary table 31 will be thrown outward thereby into the separating chamber under the influence of centrifugal force, and will be distributed into the path of the air current rising in the separating chamber, as more fully hereinafter described. A

To cause the air current to move upward through theseparating chamber, a fan 57 may be provided comprising vanes 59 secured to a hub 61 mounted on a short sleeve 63 projecting upward from a cone 65 encircling the feed tube 29. The cone 65 has 7 a flange 67 at the lower end thereof mounted on a ring 69 above the distributer table 31 and secured thereto by bolts 71, said ring 69 being spaced above said table by sleeves 7 3 on said bolts. Thus, the fan 57 is supported by the distributor table 31 through'the intermediary of the cone 65., and is rotated by the same transmission which serves to rotate said table. 7 i

The fan may be located above the ring plate 75 secured to and projecting'outward from the upper edge of the conical wall 19 of the inner casing.

To contribute to the guidance of the air current and fines whirled by the fan outwardly from the separating chamber into the collecting chamber, a cone casing 77 may be provided having a base 79 above the fan and with a diameter desirably substantially the same as the'diameter of the ring plate referred to; This cone casing may be conveniently secured to and supported by the feed tube 29 which projects downward therethrough. This cone casing 77 may cooperate with the upperconical wall 5 of the outer casing, and contribute to the guidance of the air current upward toward the head 11 of the outer casing, and tend to prevent eddy currents ofthe air as it whirls upwardly. Suitable means may be provided to conduct the air current from the collecting chamber back to the lower end ofthe separating chamber. a This means, in the present instance, comprises a throat 80 encircling the feed tube 29 and projecting through the head of the outer casing. A pipe 81 leads from this throat laterally outward and thence downward along the outer casing and communicates with a pipe 83 projecting obliquely upwardly through the lower conical wall 3 of the outer casing, the upper end of-said pipe 83 being connected to and communicating with the lower conical wall 17 of the inner casing. The air current on leaving the collecting chamber will pass through the pipes 81 and 83 and return to the separating chamber. To control the air current passing through the pipe '81, a'valve 85 may be mounted therein and have a handle 87 to facilitate adjustment of the valve to vary the draft through the pipe 81 as desired. r

The air current rising upwardly through the separating chamber will pass along the lower conical wall 17 of the inner casing, and thence along the upper conical wall 19 of said casing, and substantially at thejuncture of said walls will receive'the materials thrown outward by centrifugal force by the rotary distributor table 31'. The heavier particles or tailings will gravitate clownward along the lower conical wall 17 and V weight 95 and open said valve, and allow discharge of the tailings' through the outlet 89. Thereupon, the weight 95 will serve automatically to'return the valve to closed position. 7 r

The centrifugal effect of the rotary distributer onthe materials, andthe whirling effect on the air produced by the fan will tend to cause the materials to be thrown outwardly' toward the upper conical wall 19 of the separating chamber, and the materials will be thrown outward different distances depending on their relative weights or other characteristics thereof. This will tend to prevent the t'ailings from impinging upon and pulling'the "fines downward through the separating chamber, and thereby contribute to the 'eflicient separation of the materials. The fines will moveupward with the rising air current, and be whirled by the fan outwardly between the ringplate 75 and'thecone casing base 79 into the collecting chamber. The centrifugal efiect of the whirling air" current will tend tothrow the fines against the upper conical wall 5 of the outer casing, and they will be deflected downward thereby, and flow thence along the lower conical wall 30f the 'outer casing, and be discharged through the fines outlet 9. The air current will whirl in a long spiral'path upward from the fan to the throat 80, and pass thence through the pipes 81 and 83 and return to the separating chamber. Thus, the air will pass in a closed circuit upward through the separating chamber outward past the fan into the collecting chamber, and thence upward and through the pipes in a closed circuit.

The separatordescribed is simple in construction, and serves efficiently to separate the materials to be graded introduced into the separator.

It will be understood that the invention is not limited to the specific embodiment shown, and that various deviations'may be made therefrom without departing from the spirit and scope of the appended claims.

What is claimed is 1. An air separator for grading materials, comprising, in combination, an outer casing, an inner casing therein dividing the same into a separating chamber and a collecting chamber, said inner casing positioned a substantial distance from the upper end of the outer casing, a hopper at the top of the casing, a feed tube extending from the hopper down to the separating chamber, a member supported by said tube in spaced relation to the upper end of the separating chamber and cooperating with the upper end of said chamber to form a restricted fan receiving space, a fan rotatable in said restricted space to cause an air current to circulate upward through the separating chamber into the collecting chamber, and a conduit for conducting air from the upper end of the collecting chamber to the lower end of the separating chamber and in an upward direction through said lower end.

2. An air separator for grading materials, comprising, in combination, an outer casing, an inner casing therein dividing the same into a separating chamber and a collecting chamber, a by-pass pipe leading from the upper end of the collecting chamber to the lower end of the separating chamber, a fan above the separating chamber for causing an air current tocirculate through the separating chamber, collecting chamber and bypass pipe in a closed circuit, a feed tube projecting from the top of the outer casing downward into the separating chamber to deliver materials to be graded therein, and means intermediate the top of the outer casing and the fan to contribute to the guidance of the air from the collecting chamber to the by-pass pipe, said separating chamber being constructed to direct the tailings into the by-pass pipe.

3. An air separator for grading materials, comprising, in combination, an outer casing comprising upper and lower conical walls meeting and diverging from their juncture, an inner casing comprising upper and lower conical walls meeting and diverging from their juncture and dividing the outer easing into a separating chamber and a collecting chamber, a by-pass pipe leading from the upper end of the collecting chamber to the lower end of the separating chamber, a conical member mounted in the collecting chamber above the separating chamber and spaced therefrom, a fan located intermediate said conical member and said separating chamber for causing an air current to circulate through the separating chamber, collecting chamber and bypass pipe in a closed circuit, and means to rotate said fan.

4. An air separator for grading materials, comprising, in combination, an outer casing having an opening in the top thereof, an inner casing dividing the outer casing into a separating chamber and a collecting chamber, a by-pass pipe projecting from said opening to the lower end of the separating chamber, a feed tube smaller than said opening and projecting downward therethrough toward the separating chamber for introducing materials to be graded therein, a fan for causing 'an air current to circulate through said separating chamber, collecting chamber and by-pass pipe in a closed circuit, said separating chamber constructed to direct the coarser materials into said pipe to expose the materials to the air current rising therein, and an outlet in said pipe for discharging the coarser materials.

5. An air separator for grading materials, comprising, in combination, an outer casing, an inner casing therein dividing the same into a separating chamber and a collecting chamber, a feed tube projecting through the top of the outer casing downward into the separating chamber, a rotary distributer in said separating chamber to receive materials from said feed tube, a conical member carried by said rotary distributer and encircling said feed tube, a fan mounted on said conical member, a vertical shaft for said rotary distributer, a horizontal shaft, and bevel gears on said shafts for imparting rotation from said horizontal shaft to said vertical shaft.

6. An air separator for grading materials, comprising in combination, a collecting cas ing, a separating casing therein having a downwardly converging lower end, a pipe extending downward from said converging end to conduct tailings from the separating casing, a tailing outlet in said pipe, a feeding tube projecting from the top of the collecting casing toward the separating casing, a distributer within the separating casing to receive materials from the feeding tube, a shaft for driving the distributer, means for producing an air current rising through the separating casing into the collecting casing, and a bypass conduit leading from the upper end of the collecting casing to the lower portion of said pipe to conduct an air current upwardly through the tailings in said pipe and the separating casin 7 An air separator for grading materials, comprisin in combination, an outer casing having a lines outlet at the lower end thereof and an air outlet at the upper end thereof, an inner casing in said outer casing dividing the same into a separating chamber and a collecting chamber, said separating chamber having an upper end communicating with the collecting chamber and an outlet at the lower end thereof, a pipe leading from the air outlet of the outer casing to the outlet at the lower end of the separating chamber, a tailings outlet in said pipe, means to cause an air current to circulate through the sepward, means to feed the materials to be graded downward into said separating chamber, a rotary distributer for receiving the materials and whirling the same outward into the path of the air current moving upward in the separating chamber, and driving means for said rotary distributer.

In testimony whereof, I have signed m name to this specification.

THOMAS J. STURTEVANT. 

